Evaluation of the protective effect of a prime-boost strategy with plasmid DNA followed by recombinant adenovirus expressing BmAMA1 as vaccines against Babesia microti infection in hamster

• Published in: Acta parasitologica 2018-06, Vol.63 (2), p.368-374
• Main Authors: Wang, Guanbo, Yu, Longzheng, Efstratiou, Artemis, Moumouni, Paul Franck Adjou, Liu, Mingming, Guo, Huanping, Gao, Yang, Cao, Shinuo, Zhou, Mo, Li, Jixu, Ringo, Aaron Edmond, Xuan, Xuenan
• Format: Article
• Language: English
• Subjects: Adenoviridae - genetics; Adenovirus; Adenoviruses; Animal Systematics/Taxonomy/Biogeography; Animals; Antibodies; Antibodies, Protozoan - blood; Antibody response; Antigens, Protozoan - administration & dosage; Antigens, Protozoan - genetics; Antigens, Protozoan - immunology; Babesia microti; Babesia microti - genetics; Babesia microti - immunology; Babesiosis - parasitology; Babesiosis - prevention & control; Biomedical and Life Sciences; Biomedicine; BmAMA1; Cricetinae; Deoxyribonucleic acid; DNA; DNA vaccine; DNA vaccines; Ecology; Hamsters; Hematocrit; Heterologous prime-boost; Immunization; Immunization, Secondary - methods; Immunoglobulin G; Immunoglobulin G - blood; Infections; Lymphocytes T; Medical Microbiology; Microbiology; Parasitemia; Parasitemia - prevention & control; Parasitology; Plasmids; Plasmids - administration & dosage; Plasmids - genetics; Priming; Protozoan Proteins - administration & dosage; Protozoan Proteins - genetics; Protozoan Proteins - immunology; Strategy; Vaccination - methods; Vaccines; Vaccines, DNA - administration & dosage; Vaccines, DNA - genetics; Vaccines, DNA - immunology
• ISSN: 1230-2821; 1896-1851
• DOI: 10.1515/ap-2018-0042

In the present study, we have investigated the protective effect of a heterologous prime-boost strategy with priming plasmid DNA followed by recombinant adenovirus, both expressing BmAMA1, against Babesia microti infection. Four groups consisting of 3 hamsters per group were immunized with pBmAMA1/Ad5BmAMA1, pNull/Ad5BmAMA1, pBmAMA1/Ad5Null and pNull/Ad5Null, followed by challenge infection with B. microti . Our results showed that hamsters immunized with plasmid and adenovirus expressing BmAMA1 developed a robust IgG and IgG2a antibody response against BmAMA1, suggesting the DNA vaccine or viral vector vaccine tend to induce a Th1-biased response. Compared to the control hamsters, the hamsters vaccinated either with the prime-boost strategy or one of the two “vaccines” exhibited no significant protection against B. microti challenge. Although a slight difference in terms of parasitemia and hematocrit values at days 14–16 post challenge infection was observed, no other statistical difference was detected. Our results indicate that the prime-boost vaccination strategy of injection of plasmid and adenovirus expressing BmAMA1 is not efficient in protecting against B. microti infection.